Question

market researcher tests whether watching a particular soap opera depends on the viewer's age. A random sample of adult viewers of the The Young and the Restless is collected over a 30-day period; data are presented below:

                                               Watched?

Viewer's age                 Yes             No

18-25 years 33 40

26-40 78 55

41+ years 18 84

Part a: State the null hypothesis for a two-way chi-square test involving watch status (Yes/No) and viewer's age. [3 points]

Part b: What is the expected frequency for 18-25 year olds who did NOT watch the soap? Explain how you arrived at your answer. [3 points]

Answer 1

Ans:

A)

H₀:watching a particular soap opera is independent of the viewer's age.

H_a:watching a particular soap opera depends on the viewer's age.

B)Expected frequency=row sum*column sum/308

	Observed(fo)
	Yes	No	Total
18-25	33	40	73
26-40	78	55	133
41+	18	84	102
Total	129	179	308
	Expected(fe)
	Yes	No	Total
18-25	30.57	42.43	73
26-40	55.70	77.30	133
41+	42.72	59.28	102
Total	129	179	308
	Chi sqaure=(fo-fe)^2/fe
	Yes	No	Total
18-25	0.192	0.139	0.331
26-40	8.924	6.431	15.355
41+	14.305	10.309	24.614
Total	23.421	16.879	40.300

Test statistic:

Chi square=40.30

df=(3-1)*(2-1)=2

p-value=CHIDIST(40.30,2)=0.0000

Reject the null hypothesis.